Device And Method For Converting And Preventing Conversion Of A Semi-Automatic Firearm To An Automatic Firearm

ABSTRACT

A device and method is provided for easily and readily converting a semi-automatic firearm to a fully automatic firing firearm. An additional method is provided for preventing the conversion of a semi-automatic firearm to an automatic firing firearm.

RELATED APPLICATIONS

There are no previously filed, nor currently any co-pending applications, anywhere in the world.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to firearms and, more particularly, to a device and method for converting and preventing conversion of a semi-automatic firearm to an automatic firearm.

2. Description of the Related Art

The AR10 and AR15 were invented by Armalite Corporation by a team led by Eugene Stoner in the 1950's. Armalite Corporation sold its rights concerning the Ar10 and Ar15 rifles to Colt Firearms Manufacturing Co. in 1959. The U.S. Military eventually adopted the Ar15 rifle and changed the rifle's model designation to “M16” Under U.S. law, the U.S. Military M16 rifle is defined as a machine gun, as it will continue to fire if the trigger is held in the pulled position until the shooter releases the trigger or the ammunition supply is exhausted. Later models of the US Military M16 rifle could be equipped with a burst fire option allowing it to fire a predetermined amount of ammunition with each pull of the trigger. Because M16 firearms equipped with the burst fire option are capable of firing more than one shot per single function of the trigger, such firearms are also considered a machine gun under U.S. law.

In light of the US Military renaming the Ar15 to M16, Colt Firearms Manufacturing Co. retained the Ar15 name and applied this model designation to a civilian version of the M16 rifle that was capable of semi-automatic operation only. A semi-automatic firearm is defined as a firearm that is capable of only firing one shot after manual reloading by single function of the trigger.

The Bureau of Alcohol Tobacco and Firearms (BATF) is a U.S. Government Law Enforcement agency authorized with arrest powers to enforce Federal firearms laws, issue licenses, regulate sales, require approved record keeping, arrest and seek prosecution of violators, and approve designs of firearms for sale to the civilian public. The BATF also maintains a National Firearms Association registry of machineguns to enable them to determine if a machinegun is lawfully possessed. BATF further requires firearms manufacturers to maintain records of manufacture, marking (serial number, caliber, name and address of manufacturer), and disposition of firearms. In addition, BATF regulates the sale of firearms to the civilian public through federal firearms dealers. Sales of firearms to the public are regulated by requiring license issuance and enforcing laws concerning record keeping provisions, and adhering to federal laws regarding acquisition and disposition of firearms by the dealer.

Pursuant to U.S. Law, a machine gun is a firearm that is capable of firing more than one shot without manual reloading by a single function of the trigger or a firearm that can be “readily or easily restored” to fire more than one shot without manual reloading by a single function of the trigger. Civilian ownership of machineguns is highly restrictive. In order for a civilian to acquire ownership of a machinegun, a transfer tax and a background investigation is required along with local law enforcement approval. In addition, the machinegun must have been made, registered and lawfully possessed prior to the May 19, 1986 civilian ownership ban on machineguns. In 1986, former President George H. W. Bush signed into law an amendment (Hughes Amendment, H.AMDT.777) that banned the civilian ownership or transfer of any fully automatic firearm which was not registered by May 19, 1986. This Bill was incorporated into House Bill 4332. Machineguns owned and registered before May 19, 1986 can still be legally owned and lawfully transferred if the transferor complies with national firearms act provisions.

The Ar10, Ar15 rifles and clones thereof can be quickly (two seconds) converted to fully automatic operation using a novel device and method to be described later in the present application below. The conversion to automatic operation can be performed without any modification to the firearm or firearm's parts, and can be converted back to semi-automatic operation without evidence of prior conversion.

The Ar10, Ar15 rifles and clones thereof have been manufactured and sold to the civilian public since 1964. It is estimated in the United States alone there have been over two (2) million Ar10, Ar15 rifles and clones thereof produced and sold to the civilian public. The Ar10, Ar15 rifles and clones thereof have been exported world wide since 1964. In light of the present invention, Ar10, Ar15 rifles and clones thereof can be readily and easily converted to fire fully automatic. Thus, according to U.S. Law, the Ar10, Ar15 rifles and clones thereof should be reclassified as “machineguns”. The “shoots automatically” statutory language encompasses weapons that will function automatically. The “readily restorable” statutory language encompasses weapons which were capable of shooting automatically, but not in their present condition. The “designed” statutory language encompasses those weapons which have not previously functioned as machineguns but possess design features facilitating full automatic fire by simple modification or elimination of existing component parts.

Because U.S. Law prohibits new manufacture or sales of machineguns or new registration of machineguns to the civilian public, the Ar10, Ar15 and clones thereof are arguably contraband and may be subject to seizure and forfeiture. In addition, owners in possession of the Ar10, Ar15 and clones thereof could be potentially charged with unlawful possession of a machinegun.

In the past, there have been several instances in which the BATF has approved the sale of a semi-automatic firearm to the civilian public and later discovered that the same could be easily and readily converted to full automatic operation by altering a part(s) of the firearm. One well known example of this is the Cobray SAP M-10 pistol. The Cobray SAP M-10 was manufactured as an open bolt semi-automatic firearm but it was soon discovered that its disconnector could be broken off or its contact surface could be ground off causing the firearm to operate fully automatic. As a result of its findings, the BATF halted production of all open bolt guns on Jun. 21, 1982. BATF opined the guns were “readily convertible” to full-auto capability, but grandfathered those weapons produced prior to 1981. Other firearms directly affected by the open bolt ban after they were approved for civilian sale include the following: UZI, mini UZI, and Intratec open bolt KG-9. These firearms were later modified with designs that prevented them from firing from an open bolt or hindering mechanically the firearm being easily and readily adapted to firing from an open bolt. The new designs were submitted to the BATF and subsequently approved thus allowing manufacture of the modified design of these firearms.

Colt Firearms Manufacturing Co. has patented several designs which will make the Ar15 or other similar models manufactured by Colt Firearms difficult to convert to full automatic operation, thus it is apparent easy conversion to full automatic operation is not a desirable feature in a civilian legal semi-automatic firearm. Currently patented methods concerning conversion prevention fails to prevent the present invention from providing a quick, safe and effective conversion to full automatic operation of the Ar10 Ar15 or clones thereof.

In light of BATF's prior history of conduct concerning these matters, one can easily conclude that the Ar10, Ar15 firearms and clones thereof must be redesigned or repaired in a manner so as to prevent full automatic operation and which would bring the firearms into compliance with current federal firearms laws. The counter methods described later in this application, if applied will correct the problem and prevent the Ar10, Ar15, and clones thereof from being easily and readily convertible to full-automatic operation when using the present invention's device and method of conversion.

Irrespective of the newly discovered dangers associated with currently designed Ar10, Ar15 rifles and clones thereof, the present invention has great merit. The device and method of the present application provides a simple, reliable, and effective manner for converting Ar10, Ar15 rifles and clones thereof to fully automatic operation. Law enforcement agencies would benefit. Such agencies could issue the rifles in question to an officer while retaining the device of the present invention in a safe place. The device of the present invention would be issued only when deemed necessary, thus precluding possession by law officers of the machineguns until circumstances warranted issuance thereof.

Additionally, after the firearm has been converted to full automatic operation, it may be converted back to semi-automatic operation in under two (2) seconds simply by removing the device of the present invention. No evidence will be detected concerning the prior conversion to full automatic operation. This may constitute merit when full automatic conversion is desired where such conversion is not apparent by the outward appearance of the firearm, and when conversion back to semi-automatic function is performed quickly leaving no evidence of the firearm's prior conversion. This feature would be desirable to governmental entities during clandestine operations.

Further, the U.S. Military would likely have an interest in the device of the present invention. The present device would eliminate the need for three (3) components presently required for providing the M16 rifle with automatic firing capability, namely, the full automatic sear, the full automatic sear pin, and the full automatic sear spring. Moreover, the U.S. Military or other government entity could retain control of the device of the present invention and issue it only when the need for automatic capability arose. Also, in the event of mechanical parts (trigger, hammer, or associated pins and springs) failure resulting in the inability of the firearm to fire, the firearm could be fired simply by removing the hammer, installing a weighted element, and pulling the charging handle to the rear and releasing it to initiate firing and depressing the forward bolt assist plunger to stop firing.

Accordingly, a need has arisen for a device and method by which a semi-automatic rifle or firearm can be converted to a fully automatic firing firearm in a manner which is quick, easy, and efficient, and without modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle or firearm. Additionally, a need has also arisen for a device and method for preventing conversion of a semi-automatic firearm to an automatic firearm. The development of the device and method for converting and preventing conversion of a semi-automatic firearm to an automatic firearm fulfills this need.

A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related:

U.S. Pat. No. 6,848,351 B1, issued in the name of Davies:

U.S. Pat. No. 4,658,702, issued in the name of Tatro;

U.S. Pat. No. 5,183,959, issued in the name of McCoan et al;

U.S. Pat. No. 5,827,992, issued in the name of Harris et al;

U.S. Pat. No. 5,551,179, issued in the name of Young;

U.S. Pat. No. 3,670,442, issued in the name of Kennedy et al.;

U.S. Pat. No. 6,510,778 B1, issued in the name of Irwin;

U.S. Pat. No. 4,057,003, issued in the name of Atchisson:

U.S. Pat. No. 4,142,314, issued in the name of Foote: and

U.S. Pat. No. 6,931.978 B1, issued in the name of Dionne.

Consequently, a need has been felt for a device and method by which a semi-automatic rifle or firearm can be converted to a fully automatic firing firearm in a manner which is quick, easy, and efficient, and without modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle or firearm. Additionally, a need has also arisen for a device and method for preventing conversion of a semi-automatic firearm to an automatic firearm.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide a device and method for easily and readily converting a semi-automatic firearm to a fully automatic firing firearm.

It is another object of the present invention to provide a device in the form of a weighted element for easily and readily converting a semi-automatic firearm to a fully automatic firing firearm.

It is another object of the present invention to provide a weighted element adapted to be utilized with any gas operated or blow back type of semi-automatic firearm, including pistols.

It is another object of the present invention to provide a weighted element being sizably adapted so as to be slidably carried within an elongated receptacle of the bolt carrier of a selected semi-automatic firearm.

It is another object of the present invention to provide a device which allows a semi-automatic firearm to be easily and readily converted to a fully automatic firing firearm in two (2) seconds.

It is another object of the present invention to provide a device which allows a semi-automatic firearm to be easily and readily converted to a fully automatic firing firearm without modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle firearm, including the firing mechanism/system and trigger mechanism thereof.

It is still another object of the present invention to provide a device and method for preventing conversion of a semi-automatic firearm to a fully automatic firing firearm.

Briefly described according to one embodiment of the present invention, a device and method for converting a semi-automatic rifle or firearm to a fully automatic firing firearm is disclosed. The device comprises a weighted element adapted to be utilized with any gas operated or blow back type of semi-automatic firearm, including pistols. More specifically, the weighted element is adapted to be utilized by the entire family of semi-automatic Ar 5 or M16 rifles which include but are not limited to the Ar10 and Ar15, M16, M16A1, M16A2, M16A3, M4, M4A1, and the like. The weighted element is cylindrical and defines an elongated configuration. Weighted element has a forward end defining a surface and a rearward end defining a surface. Weighted element is sizably adapted so as to be slidably carried within an elongated receptacle of the bolt carrier of a selected semi-automatic firearm. The elongated receptacle provides a circular volume within which the weighted element is adapted for reciprocating axial movement.

In order to allow the semi-automatic firearm to operate in a fully automatic firing mode, the upper receiver is pivotally disengaged from the lower receiver of the firearm. The weighted element is inserted longitudinally through a circular opening provided at the distal end of the bolt carrier. The upper receiver is pivoted downward to engage lower receiver in a removably locked relationship. The charging handle is pulled rearward to load the firearm and the weighted element is positioned posterior of hammer which is held in the sear notch position. The trigger of semi-automatic firearm is pulled and retained in a rearward pivotal position, thereby facilitating automatic mode firing of all the cartridges housed in the magazine. The semi-automatic firearm ceases firing in the automatic mode upon release of the trigger to its resting position.

The above described method for converting a semi-automatic rifle firearm to a fully automatic firing firearm requires no modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic firearm, including the firing mechanism/system and trigger mechanism thereof.

In accordance with another embodiment, weighted element is defined of a plurality of spherical bodies or globules. Collectively, upon aligning the plurality of spherical bodies in a linear, abutting manner, the spherical bodies are constructed as having diameters and an overall length allowing spherical bodies to rollably and slidably fit within the elongated receptacle of bolt carrier. The plurality of spherical bodies is adapted to function in a substantially identical manner as the elongated, cylindrical weighted element. Thus, the plurality of spherical bodies are adapted to allow a semi-automatic firearm to be readily and easily converted to a fully automatic firing firearm.

A device and method is disclosed for preventing conversion of a semi-automatic rifle or firearm to a fully automatic firing firearm. The device comprises a bolt carrier receptacle obstruction. The obstruction is adapted to provide a suitable obstruction means for effectively obstructing or blocking a blocking a weighted element or functionally comparable device from traveling in a direct linear travel path through elongated receptacle to firing pin. In accordance to one embodiment, the obstruction preferably comprises an elongated member constructed of a solid, rigid material. The obstruction is suitably mounted within the elongated receptacle of the bolt carrier. The obstruction sizably adapted so as to extend a length within the elongated receptacle, wherein such length provides a sufficient striking space therein through which the hammer of trigger mechanism is allowed to travel, thereby enabling the hammer to strike the firing pin in conformance to standard operation thereof.

In accordance to another embodiment, the obstruction is provided as a crossmember or a crosspin suitably mounted within the elongated receptacle, wherein the crossmember is adapted to provide a suitable obstruction means for effectively obstructing or blocking a direct linear travel path provided by the elongated receptacle to the firing pin without interfering or impairing the ability of the hammer to strike the firing pin in conformance to standard operation thereof. The crossmember is mounted, such as by welding, perpendicularly between lateral sidewalls forming elongated receptacle of tubular guide frame of bolt carrier.

In accordance to yet another embodiment, the bolt carrier is envisioned to be manufactured as having a solid distal end adapted to prevent both placement of a weighted element or functionally comparable device inside the elongated receptacle, and to prevent the weighted element or comparable device from reciprocating axially inside the elongated receptacle and contacting firing pin, and allowing hammer to pivot according to its standard operation.

In accordance to still another embodiment, in order to prevent a weighted element or a component being functionally comparable therewith, from being carried within the elongated receptacle of tubular guide frame so as to prevent reciprocating axial movement by the weighted element or functionally comparable device inside the elongated receptacle, the lower edges of the arcuate lateral sidewalls are milled in such a manner so as to eliminate an ability by the elongated receptacle to carry a weighted element or any functionally comparable component therein, thereby preventing conversion of a semi-automatic rifle or firearm to a fully automatic firing firearm.

The use of the present invention allows a semi-automatic rifle or firearm to be converted to a fully automatic firing firearm in a manner which is quick, easy, and efficient, and without modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle or firearm. The use of the present invention further provides a method for preventing the conversion of a semi-automatic firearm to an automatic firing firearm in a manner which is quick, easy, and efficient.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:

FIG. 1 is a right side elevational view of a gas operated, semi-automatic rifle;

FIG. 2 is a partial cross-sectional view of an upper and lower receiver and firing mechanism of the semi-automatic rifle shown in FIG. 1.

FIG. 3 is a top perspective view of a bolt carrier;

FIG. 4 is a bottom perspective view of a bolt carrier;

FIG. 5 is a top plan view of the bolt carrier illustrated in FIGS. 3 and 4, shown with the bolt key removed;

FIG. 6 Is a side elevational view of the bolt carrier shown in FIG. 3;

FIG. 7 is a cross-sectional view of the bolt carrier shown in FIG. 6 taken along lines 7-7;

FIG. 7A is a left side, partial cross-sectional view of a gas operated, semi-automatic rifle;

FIG. 7B is a left side, partial cross-sectional view of a gas operated, semi-automatic rifle illustrating expulsion of an empty cartridge case;

FIG. 7C is a left side, partial cross-sectional view of a gas operated, semi-automatic rifle illustrating the feed ramps;

FIG. 8 is a top perspective view of a weighted element, according to the preferred embodiment of the present invention;

FIG. 9 is a top plan view of the bolt carrier illustrating the weighted element carried within an elongated receptacle of bolt carrier;

FIG. 10 is a side elevational view of the bolt carrier of FIG. 9 showing weighted element carried within the elongated receptacle;

FIG. 11 is a perspective view of a plurality of spherical bodies, according to one embodiment of the present invention:

FIG. 12 is a top plan view of a bolt carrier showing the plurality of spherical bodies carried within the elongated receptacle thereof:

FIG. 13 is a side elevational view of the bolt carrier of FIG. 12 showing the plurality of spherical bodies carried within the elongated receptacle thereof;

FIG. 14 is a perspective view of a plurality of hollow spherical bodies;

FIG. 15 is a cross-sectional view of a hollow spherical body illustrating the rigid sidewall thereof encapsulating a weighted substance;

FIG. 16 is a perspective view of a bolt carrier receptacle obstruction;

FIG. 17 is a side elevational view of the obstruction shown in FIG. 16;

FIG. 18 is a top perspective view of a bolt carrier having the obstruction mounted within the elongated receptacle thereof;

FIG. 19 is a perspective view of an obstruction, according to an alternate embodiment thereof;

FIG. 20 is a bottom perspective view of a bolt carrier having the obstruction shown in FIG. 19 mounted within the elongated receptacle thereof;

FIG. 20 a is bottom perspective view of a bolt carrier manufactured as having a solid distal end;

FIG. 21 is a side elevational view of a bolt carrier showing a lower edge of a first lateral sidewall of a tubular guide frame of bolt carrier removed via milling;

FIG. 22 bottom perspective view of the bolt carrier of FIG. 21 showing a lower edge of a second lateral sidewall of the tubular guide frame of bolt carrier removed via milling;

FIG. 23 is a side elevational view of a bolt carrier indicating via broken lines the portion of the lower edge of the first lateral sidewall of the tubular guide frame to be removed;

FIG. 24 is a bottom perspective view of the bolt carrier of FIG. 23 indicating via broken lines the portion of the lower edge of the first and second lateral sidewalls of the tubular guide frame to be removed;

FIG. 25 is a top perspective view of a bolt carrier illustrating an alternative obstruction embodiment mounted within the elongated receptacle thereof;

FIG. 26 is a top plan view of the bolt carrier shown in FIG. 25;

FIG. 27 is a bottom perspective view of a bolt carrier illustrating a second alternative embodiment concerning an obstruction, wherein the obstruction is shown as a crosspin mounted perpendicularly between the lateral sidewalls inside the elongated receptacle of the bolt carrier:

FIG. 28 is a perspective view of a shroud;

FIG. 29 is a rear side elevational view of the shroud;

FIG. 30 is a top perspective view of a bolt carrier illustrating the shroud mounted within the elongated receptacle thereof; and

FIG. 31 is top plan view of a bolt carrier illustrating an alternative shroud embodiment mounted within the elongated receptacle thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT 1. Detailed Description of the Figures

Referring now to FIG. 1 a side elevational view of a gas operated, semi-automatic rifle generally designated 10 is illustrated. For purposes of this explanation, rifle 10 is shown as an AR15 designed to furnish only semi-automatic operation. However, it should be understood by one skilled in the art that the present invention can be utilized with any gas operated, direct gas impingement, or blow back type of semi-automatic firearm, including pistols. More specifically, any family of semi-automatic AR15 or M16 rifles are manufactured so as to be readily and easily adapted for utilizing the present invention. The family of semi-automatic Ar15 or M16 rifles includes but is not limited to the Ar10 and Ar15, M16, M16A1, M16A2, M16A3, M4, M4A1, M4A3, and the like. In the embodiment shown in FIG. 1, the rifle 10 includes a stock 12 mounted on a receiver 14. The receiver 14 includes a cartridge feeding device 16 mounted therein. Feeding device 16 is shown herein as a magazine 16 a, however, other feeding devices 16 are envisioned and may be utilized which include but are not limited to belt feed, drum feed, or hopper feed (all not shown). A barrel 18 is operatively connected to the receiver 14 and has a hand grip 20 mounted thereto for isolating a hand of a shooter from direct contact with the barrel 18. The receiver 14 generally houses a firing mechanism 22, wherein firing mechanism 22 generally includes a bolt carrier assembly 24 (shown in FIGS. 1 and 2) and a trigger mechanism 26. Receiver 14 is generally fabricated of metal and has a lower receiver 28 and an upper receiver 29 coupled by two pins or screws 19 and 21. Pin 21 is depressible so as to allow the upper receiver 29 to release from lower receiver 28 and pivot about pin 19 upward and downward with respect to lower receiver 28. The lower receiver 28 generally houses the trigger mechanism 26. The upper receiver 29 generally includes a longitudinal chamber 29 a or cavity into which the bolt carrier assembly 24 is reciprocably mounted therein.

Referring now to FIGS. 2-7C, the bolt carrier assembly 24 is defined as being gas operated and comprises a bolt carrier 33, a bolt 30, a bolt key 32 formed integral therewith and fixedly connected thereto, and a firing pin 40. The bolt carrier 33 carries the bolt 30 and includes a cam pin 110 riding within a cam opening 112. Bolt carrier 33 is formed into a tubular guide frame 114 which includes an upper longitudinal slot 95 formed in the upper portion thereof and a lower longitudinal slot 96 formed in the lower portion thereof. Lower longitudinal slot 96 permits the hammer 74 to extend into an elongated receptacle 116 of the bolt carrier 33 and strike the firing pin 40. Elongated receptacle 116 extends longitudinally from a forward cylindrical wall 118 of tubular guide frame 114, wherein forward cylindrical wall 118 adjoins abutment surface 98 of bolt 30. Tubular guide frame 114 includes a distal end 115 defining a circular opening 119 providing direct passage into receptacle 116. Receptacle 116 provides a circular volume within which a weighted element 120 is adapted for reciprocating axial movement. Weighted element 120 affords important, unanticipated, nonobvious functional utility as applied to semi-automatic firearms which will be described later in greater detail. Importantly, weighted element 120 is also adapted to be utilized with a fully automatic functional rifle or firearm (not shown). Particularly, in the event the automatic rifle or firearm's automatic firing function fails, weighted element 120 is adapted to be utilized with the automatic firearm in such a manner so as to facilitate automatic mode firing thereby, despite firearm's mechanical failure.

A charging handle 50 functions to pull the bolt carrier 33 rearwardly when the first round of ammunition or cartridge 100 is chambered. Thus, pulling on the charging handle 50 picks up a round of ammunition or cartridge 100 from the magazine and inserts it into the firing chamber 47.

In order to have a better understanding of the present invention and its application to semi-automatic firearms, the firing mechanisms of similar semi-automatic firearms known in the prior art will be reviewed hereinbelow. Referring now more specifically to FIG. 2, the firing mechanism 22 and lower receiver 28 of the rifle 10 shown in FIG. 1 is illustrated. The bolt 30 has three communicating longitudinal cylindrical bores 34, 36, and 38 defined therein adapted to receive an inertia firing pin 40. Firing pin 40 comprises a shaft 42 mounted so as to slidably move within the third bore 38. Shaft 42 defines an enlarged diameter portion 44 slidably mounted in the first bore 34. A number of semi-automatic firearm models may include a compression spring 46 surrounding the firing pin 40 in coaxial fashion, wherein in such semi-automatic firearm models incorporating such spring 46, the compression spring 46 extends through an annular volume defined between an outer periphery of the firing pin 40 and a cylindrical wall of the second bore 36 and seats against the enlarged diameter portion 44 and the annular volume at a base of the second bore 36. Compression spring 46 spring urges firing pin 40 rearward such that the enlarged diameter portion 44 engages a firing pin retaining pin 48 which is secured to bolt 30. When bolt carrier assembly 24 occupies its battery position in a forward extremity of the upper receiver 29 and firing pin 40 is struck upon a rear extremity thereof, firing pin 40 is adapted to be displaced forwardly, (against the bias of compression spring 46, in accordance to semi-automatic firearm models incorporating such spring 46), such that a tip of firing pin 40 contacts and fires a chambered cartridge 100.

The bolt 30 includes the longitudinal chamber 29 a in a rear portion of bolt 30 in order to allow for machining of first, second, and third longitudinal cylindrical bores 34, 36, and 38 within which firing pin 40 is mounted and to permit hammer 74 (to be described later in greater detail) rotation. A rear extremity of the bolt carrier assembly 24 is in abutting contact with a buffer 62, housed in a receiver extension 64 wherein receiver extension 64 is threadedly secured to the lower receiver 28.

Upon firing the rifle 10 shown in FIGS. 2, and 7A-7C, the bullet 102 of cartridge 100 passes through the barrel 18 of rifle 10 under the driving force of expanding powder gases and past a gas port 13 located under a front sight base 18 a of rifle 10, thereby actuating gas to be tapped from the barrel 18 and into gas port 13 which is in gas communication with barrel 18. The gases rush through gas port 13 and pass through a gas tube 15 located above barrel 18. The gas tube 15 extends longitudinally from the front sight base 18 a and connects to the bolt key 32, the bolt key 32 being fixedly connected to bolt carrier 33 inside the upper receiver 29. The gases are received by bolt key 32 and funneled therefrom into the bolt carrier 33 which forces the bolt 30 and bolt carrier 33 in opposite directions. As the bolt carrier 33 forcefully urges or retracts towards the stock 12 of rifle 10 the bolt 30 begins to rotate counterclockwise and unlocks from a forward barrel extension 18 b of barrel 18. Once bolt 30 reaches a fully unlocked position, bolt 30 moves rearward concurrently with bolt carrier 33 toward the stock 12 of rifle 10 and an empty cartridge case 101 is expelled through an opening 29 b provided along a lateral sidewall of the upper receiver 29 (as shown in FIG. 7B). Bolt 30 rotation to the fully unlocked position is facilitated by the cam pin 110 which is directed along the cam opening 112. Thus, as cam pin 110 rides along cam opening 112, bolt 30 is forced to rotate correspondingly in the direction cam pin 110 navigates along cam opening 112. Upon dissipation of the rearward momentum of the bolt carrier 33, an operating spring 113 disposed behind buffer 62 spring urges bolt carrier 33 in a forward direction to the battery position. A groove (not shown) defined in the upper receiver 29 traps cam pin 110, thereby preventing cam pin 110 and bolt 30 from rotating into a closed position. As bolt carrier 33 spring urges forwardly, locking lugs 31 of bolt 30 drive a fresh cartridge 100 from the magazine 16 and up feed ramps 49 and into the firing chamber 47 As locking lugs 31 of bolt 30 move forwardly past the forward barrel extension 18 b, the cam pin 110 is directed into a filister (not shown) defined in upper receiver 29 along which cam pin 110 is guided and causing cam pin 110 to ride along cam opening 112 and forcing bolt 30 to rotate clockwise and lock at the forward barrel extension 18 b.

The gases cause the bolt carrier assembly 24 to retract to a retracted position and urges hammer 74 back and downward about hammer's 74 mounting pivot 94 wherein hammer 74 moves out of the path of retracting bolt carrier assembly 24, whereupon in the event trigger 68 is retained in trigger's 68 depressed or second position during the downward movement of the hammer 74, a second sear abutment 84 of hammer 74 engages a hook sear abutment 88 of a disconnector 76 (to be described later in greater detail). The gases which actuate bolt carrier assembly 24 to retract cause sufficient delay in extracting an empty cartridge case 101 so as not to cause the cartridge 101 to rupture. In addition, the weight of bolt carrier assembly 24 and the compression of operating spring 113 also aids to assist in sufficient delay in extracting an empty cartridge case 101 so as not to cause the cartridge case 101 to rupture. In recoil operated firearms only, the empty cartridge case 101 imparts a rearward momentum to the bolt carrier assembly 24 which is absorbed by the compression of the operating spring 113 disposed behind buffer 62 until bolt carrier assembly 24 has reached its retracted position. During the rearward stroke, the empty cartridge case 101 is retained in engagement with the bolt carrier assembly 24 by the cartridge extractor until empty cartridge case 101 strikes a fixed ejector, whereupon empty cartridge 101 is expelled from the upper receiver 29, as described earlier and shown in FIG. 7B. Upon dissipation of the rearward momentum of the bolt carrier assembly 24, the operating spring 113 biases the buffer 62 thereby facilitating return by bolt carrier assembly 24 to the battery position, and concurrently actuating a fresh cartridge 100 to be stripped from the magazine 16 and chambering the stripped cartridge 100 in the barrel 18.

The trigger mechanism 26 is designed and configured to furnish only semi-automatic operation of the rifle 10. The trigger mechanism 26 comprises a trigger 68 being pivotally mounted within the lower receiver 28 by a transversely-oriented pivot pin 70. The trigger 68 defines an elongated upper portion which includes a forward trigger sear 72 adapted to retain the hammer 74. A disconnector 76 is also mounted on pivot pin 70, wherein disconnector 76 has a lower portion located within a groove 78 in the upper elongated portion of trigger 68. A compression spring 80 is interposed between a bottom of the groove 78 and an under side of the disconnector 76 so as to urge disconnector 76 in a clockwise direction about pivot pin 70.

The hammer 74 includes a first sear abutment 82 in a forward portion thereof and a second sear abutment 84 in an intermediate portion thereof. A number of semi-automatic firearm models include a hammer 74 which may comprise a bolt stop abutment 86 positioned adjacent a face thereof wherein bolt stop abutment 86 is adapted to engage bolt carrier assembly 24 in a manner to be described hereinbelow.

The disconnector 76 defines a vertically extending portion forming a hook sear abutment 88. Being pivotally mounted on pivot pin 70, the trigger 68 is adapted to pivot from a first position to a second position wherein first position being at which the forward trigger sear 72 of trigger 68 engages the first sear abutment 82 of the hammer 74, and wherein the second position being angularly spaced in a clockwise manner from the first position in which the hook sear abutment 88 of disconnector 76 engages the second sear abutment 84 of the hammer 74. The hammer 74 is held in a cocked, nonfiring position via cooperative interengagement between either the forward trigger sear 72 and the first sear abutment 82, or the hook sear abutment 88 and the second sear abutment 84, wherein the interengagements are respectively maintained via the bias of a trigger spring 90 and a pressure of a shooter's finger.

Upon rearward pivotal movement of trigger 68 about pivot pin 70 against the bias of the trigger spring 90, the hammer 74 swings upwardly under the bias of a hammer spring 92 about a mounting pivot 94 thereof. In the course of upward swinging between the cocked position and a firing position, in which the hammer 74 contacts the firing pin 40, the hammer 74 passes through the lower longitudinal slot 96 or aperture formed in the lower portion of bolt carrier 33. Hammer 74 includes an extreme end or terminus 97. Upon hammer 74 striking the firing pin 40, a chambered cartridge 100 is fired from the barrel 18. When bolt carrier assembly 24 retracts, the hammer 74 is urged by bolt carrier 33 in a downward or counterclockwise direction. In the event trigger 68 is retained in trigger's 68 depressed or second position during the downward movement of the hammer 74, the second sear abutment 84 of hammer 74 will engage the hook sear abutment 88 of disconnector 76 after slight displacement by disconnector 76 in a counterclockwise direction about pivot pin 70. Conversely, in the event trigger 68 is immediately returned to trigger's 68 first position after the firing of the chambered cartridge 100, hammer 74 will be retained in hammer's 74 cocked position via the engagement of the forward trigger sear 72 and the first sear abutment 82. Generally, the trigger 68 will be momentarily retained in trigger s 68 second position after the rifle 10 has been fired and therefore the retraction of the bolt carrier assembly 24 generally actuates the second sear abutment 84 to engage the hook sear abutment 88. Release of trigger 68 after second sear abutment's 84 engagement with hook sear abutment 88 has been induced, the forward trigger sear 72 of trigger 68 moves into engagement with the first sear abutment 82 of hammer 74, after the second sear abutment 84 and the hook sear abutment 88 disengage. Once this occurs, the trigger mechanism 26 is primed to fire another cartridge 100 via shooter pulling against trigger 68.

The bolt 30 includes an abutment surface 98 adapted to contact the bolt stop abutment 86 on the hammer 74 (in accordance to semi-automatic firearm models incorporating such bolt stop abutment 86). In the event second sear abutment 84 fails to engage hook sear abutment 88 in light of the removal, breakage, or alteration of hook sear abutment 88 or second sear abutment 84, or the complete removal of the disconnector 76 from the trigger mechanism 26, the bolt stop abutment 86 (in accordance to semi-automatic firearm models incorporating such bolt stop abutment 86) will engage the abutment surface 98 of bolt 30 during counter retraction of bolt carrier assembly 24.

Referring now more specifically to FIGS. 3-10, the weighted element 120, according to the preferred embodiment, is cylindrical and defines an elongated configuration. Weighted element 120 has a forward end 122 defining a surface 123 being generally flat, and a rearward end 126 defining a surface 127 being generally flat. Weighted element 120 is constructed as having a diameter and length allowing weighted element 120 to slidably fit within elongated receptacle 116 of bolt carrier 33. Weighted element 120 has a length ranging from approximately to 0.50 inches to 2.75 inches, and has a diameter ranging from approximately 0.250 inches to 0.656 inches. Weighted element 120 is constructed of a solid, rigid material, such as a metal, or a combination of metals and/or components forming a solid, rigid composite material. Weighted element 120 has a weight ranging from about 50.0 grams to 120.0 grams.

In accordance with the present invention, and with respect to FIGS. 1-10, a method is provided for converting a gas operated semi-automatic rifle 10 or firearm to a fully automatic firing firearm. In accordance with a first firing cycle, weighted element 120 is adapted and configured to allow a semi-automatic rifle 10 or firearm to be converted to full automatic firearm function by inserting weighted element 120 longitudinally through the circular opening 119 provided at the distal end 115 of tubular guide frame 114 of bolt carrier 33. For purposes of this disclosure, semi-automatic rifle 10 or firearm is intended to include but is not limited to the following semi-automatic weapons: Ar10, Ar15, M16, M16A1, M16A2, M16A3, M4, and M4A1. Weighted element 120 is inserted through circular opening 119 and into elongated receptacle 116, within which weighted element 120 is slidably carried. Receptacle 116 provides a circular volume within which weighted element 120 is adapted for reciprocating axial movement. Upon pulling the trigger 68, or upon rearward pivotal movement of trigger 68 about pivot pin 70, the hammer 74 swings upwardly about mounting pivot 94, passing through the lower longitudinal slot 96 of bolt carrier 33 and contacts the firing pin 40, thereby causing the bullet 102 of cartridge 100 to pass outwardly through the barrel 18 under the driving force of expanding powder gases and imparting a rearward momentum to the bolt carrier 33 of bolt carrier assembly 24 so as to move bolt carrier 33 in a rearward direction. When trigger 68 is retained in trigger's 68 depressed or second position after the rifle 10 has been fired, retraction of the bolt carrier 33 actuates the second sear abutment 84 to engage the hook sear abutment 88, thereby maintaining hammer 74 below elongated receptacle 116 of bolt carrier 33. Weighted element 120 has a resting inertia which causes weighted element 120 to move rearwardly upon rearward movement by bolt carrier 33 thereby actuating contact by the rearward end 126 of weighted element 120 with the buffer 62. Buffer 62 absorbs rearward firing force or momentum of weighted element 120 and utilizes such force to create a forward momentum in weighted element 120. Forward momentum created by buffer 62 moves weighted element 120 in a forward axial direction through receptacle 116 causing the forward end 122 of weighted element 120 to contact firing pin 40, thereby causing a second bullet 102 of cartridge 100 to pass outwardly through the barrel 18 in automatic succession, and thus allowing the semi-automatic rifle 10 to operate in a fully automatic mode. In accordance with a second firing cycle, the firing of the second bullet 102 of cartridge 100 outwardly through the barrel 18 under the driving force of expanding powder gases again imparts a rearward momentum to the bolt carrier 33 of bolt carrier assembly 24 so as to move bolt carrier 33 in a rearward direction, thereby actuating contact by the rearward end 126 of weighted element 120 with the buffer 62. Buffer 62 absorbs rearward firing force or momentum of weighted element 120 and utilizes such force to create a forward momentum in weighted element 120. The forward momentum created by buffer 62 moves weighted element 120 in a forward axial direction through receptacle 116 causing the forward end 122 of weighted element 120 to contact firing pin 40, thereby causing a third bullet 102 of cartridge 100 to pass outwardly through the barrel 18 in automatic succession. At this point, upon maintaining trigger 68 in the rearward pivotal position, weighted element 120 begins a third firing cycle as described in the first and second firing cycles and a number of identical cycles are repeated so as to facilitate the firing of cartridges 100 in fully automatic mode until all cartridges 100 are fired from the magazine 16. The rifle 10 will cease firing in the automatic mode upon release of the trigger 68 to its first position or resting position. Release of trigger 68 causes the forward trigger sear 72 of trigger 68 to engage the first sear abutment 82 of hammer 74, thereby retaining hammer 74 in a sear notch level position or a “cocked position” While in its sear notch level position, hammer 74 obstructs the forward movement of weighted element 120, thereby preventing weighted element 120 from contacting firing pin 40 and firing another bullet 102. However, rifle 10 will again operate in the fully automatic mode upon pulling and holding trigger 68 in its second position or rearward pivotal position.

Importantly, shooter may fire single shots with a quick pull and release of the trigger 68, or may fire as many shots as desired by pulling and retaining the trigger 68 in a rearward pivotal position. Shooter may again discontinue firing by releasing the trigger 68 and may initiate firing simply by pulling the trigger 68. This procedure may be repeated as warranted or as needed until ammunition in the feeding device 16 is exhausted.

Thus, in accordance with the present invention, the method for converting a gas operated semi-automatic rifle 10 or firearm to a fully automatic firing firearm comprises the following steps: moving a safety switch 140 to a safe position; depressing the depressible pin 21 so as to pivotally disengage the upper receiver 29 from the lower receiver 28; pivoting the upper receiver 29 slightly upward so as to expose the circular opening of the tubular guide frame 114 of bolt carrier 33: examining the hammer 74 to ensure the hammer 74 is in a sear notch level position; inserting the weighted element 120 longitudinally through the circular opening 119 and into the elongated receptacle 116 of the tubular guide frame 114 of the bolt carrier 33: pivoting upper receiver 29 downward to engage lower receiver 28 in a snap-fit attached arrangement; moving the safety switch 140 to a fire position: pulling the charging handle 50 rearward, positioning the weighted element 120 posterior of the hammer 74, the hammer 74 being oriented in the sear notch level position, and releasing charging handle 50 in order to load the firearm 10; and pulling and retaining the trigger 68 in a rearward pivotal position thereby facilitating automatic mode firing of the cartridges 100 housed in the magazine 16 until releasing the trigger 68, thereby ceasing firing of the cartridges 100. Shooter may fire single shots with a quick pull and release of the trigger 68, or may fire as many shots as desired by pulling and retaining the trigger 68 in a rearward pivotal position. Shooter may again discontinue firing by releasing the trigger 68 and may initiate firing simply by pulling the trigger 68. This procedure may be repeated as warranted or as needed until ammunition in the feeding device 16 is exhausted.

Importantly, the above described method for converting a semi-automatic rifle 10 or firearm to a fully automatic firing firearm requires no modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle 10 or firearm, including the firing mechanism/system 22 and trigger mechanism 26.

For exemplary purposes, where semi-automatic rifle 10 Is an Ar15 weighted element 120, when utilized in the above described method for converting a semi-automatic rifle 10 or firearm to a fully automatic firing firearm, preferably has a length of approximately 1.75 inches, a diameter measuring approximately 0.594 inches, and a weight of approximately 72.2 grams.

Referring now to FIGS. 11-13, in accordance with another embodiment, weighted element 120 a is defined of a plurality of spherical bodies 130 or globules 132. Three (3) spherical bodies 130 are illustrated in FIGS. 11-13, however greater or less than three (3) spherical bodies 130 may be utilized. The plurality of spherical bodies 130 are each constructed so as to have substantially similar diametric measures. Collectively, upon aligning the plurality of spherical bodies 130 in linear, abutting manner, the spherical bodies 130 are constructed as having diameters and an overall length allowing spherical bodies 130 to rollably and slidably fit within receptacle 116 of bolt carrier 33. Each of the plurality of spherical bodies 130 is constructed preferably of a solid, rigid material such as metal, e.g. steel. It is envisioned that the spherical bodies 130 may also be constructed of a hollow configuration (shown in FIG. 14), the hollow spherical bodies 130 a each defined of a strong, rigid external circumferential sidewall 131 adapted to sealably encapsulate a weighted substance 133, such as mercury (shown in FIG. 15). The external circumferential sidewall 131 is constructed of an incompressible fabrication material of sufficient strength so as to be resistant to indentations, cracks, or other damage when contacted by or delivering an extreme, forceful impact.

The plurality of spherical bodies 130 has a collective weight ranging from about 50.0 grams to 120.0 grams. The plurality of spherical bodies 130 a (including weighted substance 133) has a collective weight ranging from about 50.0 grams to 120.0 grams. The plurality of spherical bodies 130, 130 a is adapted and configured to allow a semi-automatic rifle 10 or firearm to be converted to full automatic firearm function by inserting spherical bodies 130 or 130 a through the circular opening 119 provided at the distal end 115 of tubular guide frame 114 of bolt carrier 33. The spherical bodies 130 or 130 a are inserted through circular opening 119 and into elongated receptacle 116, within which spherical bodies 130 or 130 a are rollably and slidably carried. Receptacle 116 provides a circular volume within which spherical bodies 130 or 130 a are adapted for reciprocating axial movement. Upon pulling the trigger 68, the spherical bodies 130 or 130 a function in the same manner as described above concerning elongated cylindrical weighted element 120 with respect to the firing cycles. Thus, the plurality of spherical bodies 130, 130 a is adapted and configured to allow a semi-automatic rifle 10 or firearm to be converted to full automatic firearm function by simply inserting the spherical bodies 130 or 130 a through the circular opening 119 provided at the distal end 115 of tubular guide frame 114 of bolt carrier 33. Like the elongated cylindrical weighted element 120, the spherical bodies 130, 130 a allow for the conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm without modifications adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle 10 or firearm, including the firing mechanism/system 22 and trigger mechanism 26.

Thus, in further accordance with the present invention, the method for converting a gas operated semi-automatic rifle 10 or firearm to a fully automatic firing firearm comprises the following steps: moving a safety switch 140 to a safe position; depressing the depressible pin 21 so as to pivotally disengage the upper receiver 29 from the lower receiver 28; pivoting the upper receiver 29 slightly upward so as to expose the circular opening of the tubular guide frame 114 of bolt carrier 33; examining the hammer 74 to ensure the hammer 74 is in a sear notch level position; inserting the plurality of spherical bodies 130 or 130 a longitudinally through the circular opening 119 and into the elongated receptacle 116 of the tubular guide frame 114 of the bolt carrier 33; pivoting upper receiver 29 downward to engage lower receiver 28 in a snap-fit attached arrangement; moving the safety switch 140 to a fire position; pulling the charging handle 50 rearward, positioning the plurality of spherical bodies 130 or 130 a posterior of the hammer 74, the hammer 74 being oriented in the sear notch level position, and releasing charging handle 50 in order to load the firearm 10; and pulling and retaining the trigger 68 in a rearward pivotal position, thereby facilitating automatic mode firing of the cartridges 100 housed in the magazine 16 until releasing the trigger 68, thereby ceasing firing of the cartridges 100.

For exemplary purposes, where semi-automatic rifle 10 is an Ar15, the plurality of spherical bodies 130 or 130 a, when utilized in the above described method for converting a semi-automatic rifle 10 or firearm to a fully automatic firing firearm, preferably has a collective length of approximately 1.75 inches, a collective weight of approximately 72.2 grams, and each spherical body 130 or 130 a preferably having a diameter measuring approximately 0.594 inches.

Consequently, in light of the discovery concerning the above described innovative methods for converting a semi-automatic rifle 10 or firearm to a fully automatic firing firearm, a device and method is now provided for preventing conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm. Referring now to FIGS. 16-18, a bolt carrier receptacle obstruction 150 is provided. The obstruction 150 is adapted to provide a suitable obstruction means for effectively obstructing or blocking a weighted element 120, 120 a or functionally comparable device from traveling in a direct linear path through elongated receptacle 116 to firing pin 40. In accordance to one embodiment, the obstruction 150 preferably comprises an elongated member 152 constructed of a strong, solid, rigid material such as metal, e.g. steel. Obstruction 150 is suitably mounted, such as by welding, within the elongated receptacle 116 of the bolt carrier 33. Obstruction 150 preferably defines a length and diameter adapted to substantially fill or plug the circular volume provided by elongated receptacle 116, thereby providing a suitable obstruction means for effectively obstructing or blocking a direct linear travel path provided by elongated receptacle 116 to firing pin 40. Obstruction 150 is further defined as being sizably adapted so as to extend a length within elongated receptacle 116, wherein such length provides a sufficient striking space 160 therein through which hammer 74 is allowed to travel, thereby enabling hammer 74 to strike the firing pin 40 in conformance to standard operation thereof.

Obstruction 150 preferably defines a circular cross-section and is of a solid configuration. Obstruction 150 has a rearward end 154 defining a surface 155, and a forward end 157 defining a surface 158. Obstruction 150 may be designed and configured with a forward end 157 defining a beveled surface 159, shown in FIG. 19. This particular embodiment is suitably mounted within elongated receptacle 116 in a manner such that beveled surface 159 faces firing pin 40 and surface 159 is directed toward the lower longitudinal slot 96 of bolt carrier 33, as illustrated in FIG. 20. Beveled surface 159 is adapted to allow obstruction 150 to comprise a greater length without interfering or impairing the ability of hammer 74 to strike the firing pin 40. Beveled surface 159 allows for a sufficient striking space through which hammer 74 may strike firing pin 40 in conformance to standard operation thereof.

Thus, in accordance to the present invention, the method for preventing conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm comprises the following steps: mounting obstruction 150 within the elongated receptacle 116 of the bolt carrier 33, the obstruction 150 defining a length and diameter adapted to substantially fill a circular volume provided by elongated receptacle 116, thereby providing a suitable obstruction means for effectively obstructing or blocking a weighted element 120, 120 a or functionally comparable device from traveling in a direct linear path provided by elongated receptacle 116 to firing pin 40, and wherein the obstruction 150 is sizably adapted so as to extend a length within elongated receptacle 116, wherein the length of the obstruction 150 provides a sufficient striking space 160 in the elongated receptacle 116 through which hammer 74 is allowed to travel, thereby enabling hammer 74 to strike the firing pin 40 in conformance to standard operation thereof.

In the event obstruction 150 is designed and configured as having a forward end 157 defining a beveled surface 159, the method for preventing conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm comprises the following steps: mounting obstruction 150 within elongated receptacle 116 in a manner such that the beveled surface 159 of obstruction 150 faces the firing pin 40 and beveled surface 159 is directed toward the lower longitudinal slot 96 of bolt carrier 33, the obstruction 150 defining a length and diameter adapted to substantially fill a circular volume provided by elongated receptacle 116, the beveled surface 159 is adapted to allow for a sufficient striking space through which hammer 74 may strike firing pin 40 in conformance to standard operation thereof, the obstruction 150 thereby providing a suitable obstruction means for effectively obstructing or blocking a direct linear travel path provided by elongated receptacle 116 to firing pin 40.

Referring now to FIG. 20 a, in accordance to another embodiment, the bolt carrier 33 is envisioned to be manufactured as having a solid distal end 115 a adapted to prevent placement of a weighted element 120, 120 a or functionally comparable device inside the elongated receptacle 116, and to prevent the weighted element 120, 120 a or comparable device from reciprocating axially inside the elongated receptacle 116 and contacting firing pin 40. The bolt carrier 33 with solid distal end 115 a is designed and configured so as to allow the hammer 74 to pivot according to its standard operation and strike firing pin 40. Thus, the bolt carrier 33 with solid distal end 115 a does not impede or obstruct hammers 74 standard functional operation. In accordance with the present invention, a first alternative method for preventing conversion of a semi-automatic firearm to a fully automatic firing firearm comprises the following steps: manufacturing a bolt carrier 33 for a semi-automatic firearm 10, said bolt carrier 33 comprising: a tubular guide frame 114, the tubular guide frame 114 defining a proximal end opposing a solid distal end 115 a, the proximal end having a cam opening 112 defined therein, the tubular guide frame 114 includes an upper longitudinal slot 95 formed in the upper portion thereof and a lower longitudinal slot 96 formed in the lower portion thereof, said tubular guide frame 114 having a forward cylindrical wall 118; a receptacle 116 extending longitudinally between the upper longitudinal slot and lower longitudinal slot; and a bolt 30, the bolt 30 having a firing pin 40 operationally coupled thereto.

Referring now to FIGS. 21-24, in accordance to another embodiment, in order to prevent a weighted element 120 or a device functionally comparable therewith, from being carried within elongated receptacle 116 so as to prevent reciprocating axial movement by the weighted element 120 or functionally comparable device inside elongated receptacle 116, the lower edges of arcuate lateral sidewalls 114 a and 114 b of tubular guide frame 114 which extend integrally into lower longitudinal slot 96 are milled in such a manner so as to eliminate an ability by elongated receptacle 116 to carry a weighted element 120 or any functionally comparable component therein, thereby preventing conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm. More specifically, the lower edge of the first lateral sidewall 114 a (FIG. 21) of tubular guide frame 114 and the lower edge of the second lateral sidewall 114 b (FIG. 22) of tubular guide frame 114 are shown removed via milling or other suitable means for cutting, shaping, and/or dressing metal surfaces. Portions of the lateral sidewalls 114 a, 114 b have been removed to a degree which eliminates a measure of circumferential surface area of tubular guide frame 114 required for supporting a weighted element 120 or any functionally comparable device within elongated receptacle 116. Broken lines 117 in FIGS. 23 and 24 indicate specific portions of the sidewalls 114 a, 114 b that have been removed.

Thus, in accordance with the present invention, a second alternative method for preventing conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm comprises the following steps: milling the lower edge of the first lateral sidewall 114 a of the tubular guide frame 114; and milling the lower edge of the second lateral sidewall 114 b of the tubular guide frame 114 in a manner so as to eliminate an ability by the elongated receptacle 116 of tubular guide frame 114 to carry a weighted element 120 or any functionally comparable device therein.

Referring now to FIGS. 25-27, in accordance to still another embodiment, obstruction 150 a is provided as a crossmember 170 or crosspin 170 a suitably mounted within elongated receptacle 116, wherein crossmember 170 is adapted to provide a suitable obstruction means for effectively obstructing or blocking a direct linear travel path provided by elongated receptacle 116 to firing pin 40 without interfering or impairing the ability of hammer 74 to strike the firing pin 40 in conformance to standard operation thereof.

Crossmember 170 is mounted, such as by welding, perpendicularly between lateral sidewalls 114 a and 114 b forming elongated receptacle 116. Crossmember 170 is sizably shaped and configured so as to prevent a foreign object (not shown) from contacting firing pin 40, in the event a foreign object is inserted within elongated receptacle 116. Foreign object is intended to include, for example, a weighted element 120 or 120 a as described above, or any functionally comparable device. Crossmember 170 is mounted between lateral sidewalls 114 a and 114 b within elongated receptacle 116 in a manner which allows bolt carrier 33 to function in accordance to standard bolt carrier 33 operation.

FIG. 27 illustrates obstruction 150 a provided as a crosspin 170 a suitably mounted perpendicularly between lateral sidewalls 114 a and 114 b inside elongated receptacle 116.

Therefore, in further accordance with the present invention, a third alternative method for preventing conversion of a semi-automatic rifle 10 or firearm to a fully automatic firing firearm comprises the following steps: mounting crossmember 170 perpendicularly between the first lateral sidewall 114 a and the second lateral sidewall 114 b of tubular guide frame 114, the crossmember 170 is sizably shaped and configured so as to prevent a foreign object from contacting the firing pin 40 in the event the foreign object is inserted within elongated receptacle 116, the crossmember 170 is mounted between the first lateral sidewall 114 a and the second lateral sidewall 114 b within the elongated receptacle 116 in a manner which allows the bolt carrier 33 to function in accordance to standard bolt carrier 33 operation.

Referring now to FIGS. 28-30, in accordance to yet another embodiment, obstruction 150 b comprises a shroud 180 suitably mounted, such as by welding inside the elongated receptacle 116 of bolt carrier 33, a position to firing pin 40. More specifically, the shroud 180 is mounted to the forward cylindrical wall 118, the first lateral sidewall 114 a, and the second lateral sidewall 114 b of tubular guide frame 114. The shroud 180 is adapted to shield the firing pin 40 against contact by a weighted element 120, 120 a or functionally comparable device, where weighted element 120, 120 a or functionally comparable device has been inserted into the elongated receptacle 116 of bolt carrier 33. Shroud 180 comprises a linearly elongated, arcuate-shaped body 182 fabricated of a strong, rigid material. Body 182 includes a first circumferential sidewall 185 extending integrally to a second circumferential sidewall 186, and an open front end 187 A front peripheral edge 187 a of the body 182 is mounted to the forward cylindrical wall 118, the first circumferential sidewall 185 is mounted to the second lateral sidewall 114 b, and the second circumferential sidewall 186 is mounted to the first lateral sidewall 114 a. The body 182 may include a downwardly depending rear sidewall 188 molded integral thereto. The arcuate-shaped body 182 of shroud 180 allows for a sufficient striking space 184 through which the hammer 74 of trigger mechanism 26 is allowed to travel, thereby enabling the hammer 74 to strike the firing pin 40 in conformance to standard operation thereof. The shroud 180 is shown mounted inside the elongated receptacle 116 in FIG. 30.

While the shroud 180 disclosed herein is described as having an arcuate shape, the shroud 180 may be designed in other shapes and configurations without departing from the spirit and scope of this invention, particularly concerning shielding the firing pin 40 against contact by a weighted element 120, 120 a or a functionally comparable device For example, as shown in FIG. 31, shroud 180 may comprise a body 182 a having a plurality of sidewalls, wherein sidewalls include a pair of horizontal sidewalls 191, 192 joined integrally by a vertical sidewall 190. The horizontal walls 191, 192 are shown mounted to the forward cylindrical wall 118 in a manner so as to shield or cover the firing pin 40.

2. Operation of the Preferred Embodiment

To use the present invention, user moves the safety switch 140 to a safe position, depresses the depressible pin 21 so as to pivotally disengage the upper receiver 29 from the lower receiver 28, and pivots the upper receiver 29 slightly upward so as to expose the circular opening of the tubular guide frame 114 of bolt carrier 33. User next examines the hammer 74 to ensure the hammer 74 is in a sear notch level position, and inserts the weighted element 120 longitudinally through the circular opening 119 and into the elongated receptacle 116 of the tubular guide frame 114 of the bolt carrier 33. User then pivots the upper receiver 29 downward to engage lower receiver 28 in a snap-fit attached arrangement, and moves the safety switch 140 to a fire position. Next user pulls the charging handle 50 rearward, positions the weighted element 120 posterior of the hammer 74, the hammer 74 being oriented in the sear notch level position, and releases the charging handle 50 in order to load the firearm 10. Finally, user pulls and retains the trigger 68 in a rearward pivotal position, thereby facilitating automatic mode firing of all the cartridges 100 housed in the magazine 16, or until release of the trigger 68.

The use of the present invention allows a semi-automatic rifle 10 or firearm to be converted to a fully automatic firing firearm in a manner which is quick, easy, and efficient, and without modifications, adjustments, alterations and/or removal or replacement of parts concerning a selected semi-automatic rifle 10 or firearm.

Therefore, the foregoing description is included to illustrate the operation of the preferred embodiment and is not meant to limit the scope of the invention. As one can envision, an individual skilled in the relevant art, in conjunction with the present teachings, would be capable of incorporating many minor modifications that are anticipated within this disclosure. The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. Therefore the scope of the invention is to be broadly limited only by the following Claims. 

1. A method for preventing conversion of a semi-automatic firearm to a fully automatic firing firearm, said method comprising the steps of: (a) mounting an obstruction within an elongated receptacle of a bolt carrier of a semi-automatic firearm.
 2. The method of claim 1, wherein said obstruction defining a length and diameter adapted to substantially fill a circular volume provided by the elongated receptacle, thereby effectively obstructing or blocking a weighted element or a functionally comparable device from traveling in a direct linear path extending through the elongated receptacle to a firing pin of a bolt assembly of the semi-automatic firearm, and thus preventing contact by the weighted element or the functionally comparable device with the firing pin.
 3. The method of claim 2, wherein said obstruction is sizably adapted so as to extend a length within the elongated receptacle, wherein said length of said obstruction allows for a sufficient striking space in the elongated receptacle through which a hammer of a trigger mechanism of the semi-automatic firearm is allowed to travel, thereby enabling the hammer to strike the firing pin in conformance to a standard operation thereof.
 4. The method of claim 1, wherein said obstruction comprises an elongated member, said elongated member has a forward end defining a surface, and a rearward end defining a surface.
 5. The method of claim 1, wherein said obstruction comprises an elongated member, said elongated member has a forward end defining a beveled surface, and a rearward end defining a surface.
 6. The method of claim 5, wherein said obstruction is mounted within the elongated receptacle in such a manner whereby said beveled surface faces the firing pin, and said beveled surface is directed toward a lower longitudinal slot of the bolt carrier.
 7. The method of claim 1, wherein said obstruction defines a circular cross-section, and wherein said obstruction is constructed of a strong, rigid material.
 8. The method of claim 1, wherein said obstruction is defined as a crossmember or a crosspin suitably mounted perpendicularly between a first lateral sidewall and a second lateral sidewall forming the elongated receptacle.
 9. The method of claim 8 wherein said crossmember is sizably shaped and configured so as to obstruct a weighted element or a functionally comparable device from traveling in a direct linear path extending through the elongated receptacle to a firing pin, thereby preventing contact by the weighted element or the functionally comparable device with the firing pin.
 10. The method of claim 1, wherein said obstruction comprises a shroud, said shroud is suitably mounted inside the elongated receptacle of the bolt carrier, a position to a firing pin of a bolt assembly of the semi-automatic firearm, wherein said shroud is adapted to shield the firing pin against contact by a weighted element or a functionally comparable device.
 11. The method of claim 10, wherein said shroud is mounted to the forward cylindrical wall of a tubular guide frame of the bolt carrier.
 12. The method of claim 10, wherein said shroud is mounted to the forward cylindrical wall, the first lateral sidewall, and the second lateral sidewall of a tubular guide frame of the bolt carrier.
 13. The method of claim 12, wherein said shroud comprises a linearly elongated, arcuate-shaped body fabricated of a strong, rigid material, said body includes a first circumferential sidewall extending integrally to a second circumferential sidewall, and an open front end.
 14. The method of claim 13, wherein said body includes a front peripheral edge mounted to the forward cylindrical wall, said first circumferential sidewall is mounted to the second lateral sidewall, and said second circumferential sidewall is mounted to the first lateral sidewall.
 15. The method of claim 14, wherein said body is designed and configured so as to provide a sufficient striking space through which the hammer of a trigger mechanism of the semi-automatic firearm is allowed to travel, thereby enabling the hammer to strike the firing pin in conformance to standard operation thereof.
 16. The method of claim 14, wherein said body further includes a downwardly depending rear sidewall molded integral thereto.
 17. A method for preventing conversion of a semi-automatic firearm to a fully automatic firing firearm, said method comprising the steps of: (a) milling a lower edge of a first lateral sidewall of a tubular guide frame of a bolt carrier of the semi-automatic firearm; and (b) milling a lower edge of a second lateral sidewall of the tubular guide frame, wherein the lower edge of the first lateral sidewall and the lower edge of the second lateral sidewall are milled in such a manner and to a degree so as to eliminate an ability by an elongated receptacle of the tubular guide frame to carry a weighted element or any functionally comparable device therein.
 18. A method for preventing conversion of a semi-automatic firearm to a fully automatic firing firearm, said method comprising the steps of: (a) manufacturing a bolt carrier for a semi-automatic firearm, said bolt carrier comprising: a tubular guide frame, said tubular guide frame defining a proximal end opposing a solid distal end, said proximal end having a cam opening defined therein, said tubular guide frame includes an upper longitudinal slot formed in the upper portion thereof and a lower longitudinal slot formed in the lower portion thereof, said tubular guide frame having a forward cylindrical wall; a receptacle extending longitudinally between the upper longitudinal slot and the lower longitudinal slot; and a bolt, said bolt having a firing pin operationally coupled thereto.
 19. The method of claim 18, wherein said solid distal end is adapted to prevent placement of a weighted element or a functionally comparable device inside the elongated receptacle, and wherein said solid distal end is further adapted to prevent the weighted element or the functionally comparable device from reciprocating axially inside the elongated receptacle and contacting the firing pin, the bolt carrier is designed and configured so as to allow a hammer of a trigger mechanism of the semi-automatic firearm to pivot and strike the firing pin according to a standard operation of the hammer. 